Search results for "Reactive"
showing 10 items of 1469 documents
Interplays between nitric oxide and reactive oxygen species in cryptogein signalling
2014
The cellular messenger nitric oxide (NO) has many functions in plants. In this study, we investigated its interplays with Reactive Oxygen Species (ROS) in the defense responses triggered by the elicitin cryptogein produced by the oomycete Phytophthora cryptogea. The production of NO induced by cryptogein in tobacco cell suspensions was partly regulated through a ROS-dependent pathway involving the NADPH oxidase NtRBOHD. In turn, NO down-regulated the level of H2O2 derived from NtRBOHD activity. Both NO and ROS synthesis appeared to be under the control of two redundant isoforms of histone deacetylases of type 2 acting as negative regulators of cell death. Occurrence of an interplay between …
Serum antinuclear autoantibodies are associated with measures of oxidative stress and lifestyle factors - analysis of LIPIDOGRAM2015 and LIPIDOGEN201…
2021
IntroductionOxidative stress is one of many factors suspected to promote antinuclear autoantibody (ANA) formation. Reactive oxygen species can induce changes in the antigenic structure of macromolecules, causing the immune system to treat them as “neo-antigens” and start production of autoantibodies. This study was designed to evaluate the relationship between oxidative stress markers, lifestyle factors and the detection of ANA.Material and methodsWe examined measures of oxidative stress indices of free-radical damage to lipids and proteins, such as total oxidant status (TOS), concentration of protein thiol groups (PSH), and malondialdehyde (MDA), activity of superoxide dismutase (SOD) in i…
Oxygen in Medicine
2010
The implications of oxygen for medicine are basically of two kinds. First, there is the continued need by human tissues for an adequate supply of dioxygen; if that is not met, a condition called hypoxia may arise, with serious medical consequences. There are a wide number of causes for hypoxia, and a variety of medical responses.
Molecular hydrogen (H 2 ) as a potential treatment for acute and chronic fatigue
2020
Many diseases as well as acute conditions can lead to fatigue, which can be either temporary or chronic in nature. Acute fatigue develops frequently after physical exercise or after alcohol hangover, whereas microbial infections such as influenza or COVID-19 and chronic diseases like Parkinson's disease or multiple sclerosis are often associated with chronic fatigue. Oxidative stress and a resulting disturbance of mitochondrial function are likely to be common denominators for many forms of fatigue, and antioxidant treatments have been shown to be effective in alleviating the symptoms of fatigue. In this study, we review the role of reactive oxygen and nitrogen species in fatigue and the an…
The chemistry of melatonin's interaction with reactive species
2002
Melatonin has been shown to be an effective antioxidant in a number of experimental models both in vitro and in vivo. Considering the data available, it is now clear that the indoleamine is involved in antioxidative mechanisms more complex than originally envisaged. These range from the direct radical scavenging of a variety of radicals and reactive species to the control and/or modulation of a number of processes which may trigger a redox imbalance between antioxidant and prooxidant species. This review focuses on the direct radical scavenging activity of melatonin and provides a summary of the mechanisms of the reactions between the indoleamine and reactive species in pure chemical soluti…
Antioxidation and the Hypoxic Ventilatory Response
2012
Reactive oxygen species favor the reductive state of iron. Antioxidation, by depleting biologically active ferrous iron, could then have a stabilizing effect, akin to hypoxia, on HIF-1α; the process which controls the genetic responses to hypoxia. However, the influence of antioxidation on the hypoxic ventilatory responses (HVR) is unclear. In this study we set out to determine the influence of mangiferin, a natural polyphenolic compound present in mango trees, with strong antioxidant and iron chelating properties, on the HVR. The study was performed in awake Wistar rats. Acute HVR to 12% and 8% FiO2 before and 40 min after mangiferin (300 mg/kg, i.p.) pretreatment were recorded plethysmogr…
Lipoperoxyl Radical Scavenging and Antioxidative Effects of Red Beet Pigments
2012
Aerobic life is characterized by a steady formation of reactive oxygen species and free radicals, which is almost entirely counteracted by endogenous primary and secondary antioxidant systems. Maintenance of these systems is then imperative to ensure a continuous defense to cells and to avoid conditions known as oxidative stress. Apart from antioxidant vitamins, many compounds from the plant kingdom are now considered very helpful to maintain a proper cell redox balance. Among them, betalain pigments have received recent attention. Betanin (betanidin-5-O-β glucoside) is the main betacyanin from red beet. Redox potential, ability to interact with lipid structures and bioavailability in human…
Antioxidant compound supplementation prevents oxidative damage in a Drosophila model of Parkinson's disease
2013
Loss-of-function mutations in the DJ-1 gene are linked to rare autosomal recessive forms of parkinsonism. In Drosophila, two DJ-1 orthologs have been identified, DJ-1α and DJ-1β. Several studies have shown that DJ-1β mutant flies are viable and fertile but exhibit age-dependent locomotor defects, shortened life span, and enhanced sensitivity to toxins that induce oxidative stress response compared to control flies. We also demonstrated that long-term dietary supplementation with antioxidant compounds was effective at increasing life-span values of DJ-1β mutants. These results, together with high levels of oxidative stress markers detected in newly eclosed DJ-1β mutant flies compared to cont…
Contact probe voltammetry for in situ monitoring of the reactivity of phenolic tomato (Solanum lycopersicum L.) compounds with ROS
2015
The application of an in situ electrochemical contact probe methodology for monitoring reactivity of antioxidant polyphenolic compounds in tomato fruits is described. Upon electrochemical generation of reactive oxygen species (ROS), characteristic voltammetric responses were recorded for compounds resulting from the reaction of such species with tomato compounds. This suggests that new electrochemically oxidizable compounds are generated from the oxidation of highly reactive polyphenolic compounds with ROS. Therefore, an evaluation of the antioxidant capacity of such species could be made from voltammetric data for different tomato varieties.
Antioxidant and Antiinflammatory Properties of Heme Oxygenase-1 in Osteoarthritic Articular Cells
2012
Heme oxygenase-1 (HO-1) is induced in cells by various stimuli as a defense system against oxidative stress. It is known that reactive oxygen species (ROS) participates in the initiation and progression of osteoarthritis (OA) and several antioxidant systems may protect cartilage components. HO-1 induction or CO release from CORM-2 counteracts oxidative stress and protects against proinflammatory and catabolic effects of interleukin-1β in OA chondrocytes, osteoblasts, and synoviocytes as well as in OA osteochondral explants. Both approaches have been able to downregulate the production of mediators such as reactive oxygen species, nitric oxide, matrix metalloproteinases, prostaglandin E2, cy…